Scientists show that ultraviolet (UV) light exposure leads to changes in the gut microbiome, but only in volunteers who were deficient in vitamin D.
Living at higher latitudes, which means less exposure to UV light and a greater chance of being vitamin D deficient, carries a higher risk of developing diseases such as multiple sclerosis (MS) and inflammatory bowel disease (IBD).
Research into the gut microbiome indicates that our microbial passengers may play a significant part in these conditions.
But what links vitamin D to our intestinal microbiota?
A team of researchers, many from the University of British Columbia, in Vancouver, Canada, set out to answer this question by studying how the gut microbiome responds to UV light.
When volunteers who were deficient in vitamin D received three sessions of UVB exposure, their gut microbiomes changed and bore the same hallmarks as those of study participants who were not vitamin D deficient.
The team published their findings in Frontiers in Microbiology.
UVB light boosts ‘richness’ of microbiome
The study included nine female volunteers who took vitamin D supplements in the 3 months leading up to the experiments and 12 who did not.
All participants had fair skin, specifically Fitzpatrick skin types 1 to 3.
The volunteers who had taken the supplements had vitamin D blood levels that are classed as adequate, while all but one of those who had not taken the supplements were vitamin D deficient.
All participants then had three sessions of full body exposure to UVB light. The research team saw increases in the vitamin D levels in all of the volunteers, as a result.
They then compared the composition of each participant’s gut microbiome before and after the treatments.
The authors found significant changes in the microbial compositions in the group that had been mostly vitamin D insufficient at the start of the experiment.
“Prior to UVB exposure, these women had a less diverse and balanced gut microbiome than those taking regular vitamin D supplements,” senior study author Prof. Bruce Vallance notes, summarizing the teams’ results. “UVB exposure boosted the richness and evenness of their microbiome to levels indistinguishable from the supplemented group, whose microbiome was not significantly changed.”
Specifically, the vitamin D deficient volunteers experienced an increase in Firmicutes and Proteobacteria and a decrease in Bacteroidetes, to bring their levels in line with the microbiomes of participants who had taken vitamin D supplements.
Vitamin D ‘main driver’ of shift in microbiome
Medical News Today spoke to first study author Else Bosman about the study.
“We found that vitamin D production was the main diver of the shift in the microbiome,” she explained. “It is well known that UVB light produces vitamin D, and we now start to understand that vitamin D is important to maintain a healthy gut.”
“Although those facts were known individually, this is the first study linking them up together,” Bosman continued. “The results were surprising in the way that there was a strong effect visible within 1 week’s time.”
When asked how much time we should each be spending in the sunshine to boost our vitamin D levels, Bosman urged caution.
“During the study, we made use of specialized UVB lamps that don’t cause burning. It was a therapeutically used photobooth in a clinical setting,” she explained. “From my study, it is hard to conclude how much sun exposure is enough to produce vitamin D.”
This is down to our individual skin types and the amount of UV radiation in the environment that we live in.
“Unfortunately, it is really hard to obtain enough vitamin D from diet alone, so it is wise to supplement with vitamin D during the winter,” Bosman recommended. “Your body is very efficient in making vitamin D from sunlight in the summer.”
The extent to which variations in our microbiomes resulting from fluctuating vitamin D levels affect our health is unclear at this point.
But Prof. Vallance suggests that this may be more important for people with inflammatory diseases, such as MS and IBD.
Larger studies are needed and should include the full spectrum of skin types, as well as male and female participants, the authors suggest in their paper.
“This study made use of a very selective group of participants, e.g., healthy, female, pale skin,” Bosman told MNT. “It would be very interesting to repeat the study with participants that have a lot more variety in ages and with bigger study groups to confirm the results. It would also be great if we can test if the phototherapy is useful for people with intestinal inflammation to promote their gut health.”
“The results of this study have implications for people who are undergoing UVB phototherapy and identifies a novel skin-gut axis that may contribute to the protective role of UVB light exposure in inflammatory diseases like MS and IBD.”
Prof. Bruce Vallance
Stressed Students, Bridesmaids Drama, And More: An Advice Column From A Total Amateur
Hi! A while ago I asked the BuzzFeed Community to tell me a problem they’re having, so that I — a person with absolutely zero professional qualifications to help anyone — could give them advice. So, here are the results! NBC 1. “Dear Andy,I have NO idea where I should go to school… I’m applying…
Hi! A while ago I asked the BuzzFeed Community to tell me a problem they’re having, so that I — a person with absolutely zero professional qualifications to help anyone — could give them advice. So, here are the results!
I have NO idea where I should go to school… I’m applying to 12 schools, 10 on the west coast and two in BC. I’m a high achieving student (I’m in five AP classes, president of two clubs, volunteering and a job, etc.) and I don’t want to go somewhere that’s all about the pressure, but I still want a high quality education. I’m so lost, help!”
—The Overwhelmed Student
You posted this just to dunk on all of us academically, didn’t you?
Kidding. In all seriousness, you can get a very good education at a bunch of different schools. And when you’re done, you’ll have a degree that probably nobody will ever verify! In my completely amateur opinion, the only reason people think the “Ivy League” schools are better is because a lot of wealthy, well-connected people go there (and have gone there), and therefore when you graduate from one, you’re more likely to get in at some fancy law firm or whatever because of your connections. So if you aren’t planning on being like, IDK, the CFO of Waystar Royco or something, just pick the school that you really want to go to. Where are you going to be happy living? Is one of the schools in a city you already want to move to and/or the city that has jobs in your future profession? Is it important for you to be close to home? How many Wendy’s are there on campus, and do they carry Spicy Nuggets? These are the questions you should be asking.
Oh, wait, actually…forget all that. Go to the school that will cost the least when you factor in tuition, room & board, and any scholarships you might get. Student loans are a curse and you want as little of them as possible. In the end, you might not even end up doing the thing you studied in college. Wanna know what degree I have? A BFA in Theater Performance. An acting degree. And now here I am, writing for a website. You’ll be fine.
I got married this summer, and I decided to choose only family to be my bridesmaids. For me this included three female cousins and my (now) sister-in-law. My husband, on the other hand, decided to do a mix of family as well as friends from high school for his groomsmen. I had no problem with this at all.
I had a few friends who I knew would expect to be bridesmaids, so I made it clear to them from the very beginning that I would be choosing family only as to not have a huge wedding party, but I told them they were not any less important to me and that I still wanted them to be involved in the wedding as much as they felt comfortable with. Most of the friends I had this conversation with were very understanding, however one straight up told me that she was disappointed (this was two years before the wedding).
Now it’s been a few months since I got married and this friend (a friend from childhood) started talking about the wedding. She told me she felt left out of the wedding since she wasn’t part of the wedding party. It particularly bothered her that my husband included friends and I didn’t. She then proceeded to tell me that it was difficult for her to be there the day of my wedding because of these feelings. AT MY WEDDING. She also included the fact that she didn’t want to upset me and that it doesn’t change our friendship. But if that is the case then why say anything in the first place? I’ve already said one too many times the reason for my bridesmaid choices and how important she is to me regardless. And she says she understands. I just wish she would let it go. Ever since this conversation I feel like I’ve been seeing her in a whole new light.
I do care about her feelings, but I stick by my decision and I don’t regret anything. I feel like I’ve done everything I can to make her feel better.”
—The Besieged Bride
[TL;DR: Bride had only family as bridesmaids, groom had some friends in the mix, bride’s childhood friend felt left out and complained about it a few months after the wedding.]
Question one: How drunk was your friend when she brought this up to you? If she was like, a 6 or more out of 10, I say let’s give it a pass and hope she got it out of her system.
Question two: Has your friend had a wedding of her own yet? If yes, then she should’ve understood the situation, because wedding planning is a special kind of hell and inevitably you have to make difficult decisions like this one that might hurt people’s feelings. So if you’ve planned your own wedding, you know the deal and you’re able to say to yourself, “It’s their wedding, I’m just going to be supportive and have fun.” If she hasn’t gotten married yet, she’ll realize later that it was totally inappropriate to complain about this to you. Hopefully.
I have been taking so many of the relationship quizzes on BuzzFeed but they all say I’m single. The major problem is I have an S.O. Is she just faking or am I?? Help me!! Is my girlfriend not actually mine or are we real?”
—The Quizzical Quiz-Taker
You’re not real. This is all a simulation.
—Andy (or am I?)
I’m not sure where to live. I live in Milwaukee, WI, right now. Moved here three years ago for school, but that fell through because Milwaukee is friggin expensive. My family wants me to move back to the other side of the state, towards Minneapolis/St. Paul. What should I do?”
—Meandering the Midwest
Get the fuck out of there, it’s so cold! Listen, I used to live in Michigan, and it was depressing because it was grey and miserable nine months out of the year. Now I live in Southern California, it’s sunny and beautiful and my vitamin D levels are through the roof. Migrate south, seriously.
But if you HAVE to stay, I will say that everybody who lives in Minneapolis seems to LOVE Minneapolis for some reason.
My problem is that I struggle with feeling attractive. I started taking birth control when my boyfriend and I started dating (six years ago). I started gaining the weight right after. I’m now a size 12 and my boyfriend is a slender guy. I haven’t felt attractive in the last year. I gained so much weight at one point I was a size 16. I’m back to a 12 and trying to lose weight again. I don’t feel sexy or beautiful in any way. I prefer to keep my shirt on during sex now. I don’t know why my boyfriend still finds me attractive. I have a tummy, I have rolls when I sit down, I just don’t know what he sees anymore. Any advice you could give me would be much appreciated.”
—Struggling With Size
First off, don’t worry about your boyfriend. Clearly he finds you attractive, and when you actually care about someone, the size tags on their clothes don’t matter to you at all. Appreciate that fact and find some security there.
Now, consider the possibility that if your boyfriend finds you attractive at any size, you can too! It’s not easy. It requires shedding every bit of toxic influence that the media and our society overall has thrown at you for your entire life. That takes time and work.
But if you are worried about your physical health at all, consult a doctor. There are many different types of birth control and like 40 different pills, and everyone reacts to each one differently. It can take time to find the right one, and not every doctor is going to be helpful about it. Advocate for yourself if you’re unhappy with your medication. You may have done all of this already and I’m just sitting here mansplaining BC to you, but if so at least you can cross that off your Mansplaining Bingo Card.
That’s it for this week. But if you’re having a problem that you need advice about, let me know! It could be anything: petty arguments that you need a judge to decide who was right and who was wrong, help making life decisions, relationship issues — I’m your completely unqualified man. Email email@example.com (for total anonymity) or leave a comment here!